/*
 * $Id$
 */

package edu.jas.application;


import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.StringReader;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.BufferedReader;
import java.nio.charset.Charset;
import java.util.List;

import org.apache.log4j.BasicConfigurator;

import edu.jas.gb.SolvableGroebnerBase;
import edu.jas.gb.SolvableGroebnerBaseParallel;
import edu.jas.gb.SolvableGroebnerBaseSeq;
import edu.jas.gb.SolvableGroebnerBaseSeqPairParallel;
import edu.jas.gb.SolvableReduction;
import edu.jas.gb.SolvableReductionPar;
import edu.jas.gb.SolvableReductionSeq;
import edu.jas.poly.GenPolynomialTokenizer;
import edu.jas.poly.GenSolvablePolynomial;
import edu.jas.poly.GenSolvablePolynomialRing;
import edu.jas.poly.PolynomialList;
import edu.jas.util.CatReader;


/**
 * Simple setup to run a solvable GB example. <br /> Usage: RunSGB
 * [seq|par|par+] [irr|left|right|two] &lt;file&gt; #procs
 * @author Heinz Kredel
 */

public class RunSGB {


    /**
     * main method to be called from commandline <br /> Usage: RunSGB
     * [seq|par|par+] [irr|left|right|two] &lt;file&gt; #procs
     */
    @SuppressWarnings("unchecked")
    public static void main(java.lang.String[] args) {

        BasicConfigurator.configure();

        String usage = "Usage: RunSGB " + "[ seq | par | par+ ] "
        //        + "[ seq | par | dist | cli [port] ] "
                + "[ irr | left | right | two ] " + "<file> " + "#procs ";
        //  + "[machinefile]";
        if (args.length < 3) {
            System.out.println(usage);
            return;
        }

        boolean pairseq = false;
        String kind = args[0];
        String[] allkinds = new String[] { "seq", "par", "par+" };
        // String[] allkinds = new String[] { "seq", "par", "dist", "cli"  };
        boolean sup = false;
        for (int i = 0; i < allkinds.length; i++) {
            if (kind.equals(allkinds[i])) {
                sup = true;
                if (kind.indexOf("+") >= 0) {
                    pairseq = true;
                }
            }
        }
        if (!sup) {
            System.out.println(usage);
            return;
        }
        String[] allmeth = new String[] { "irr", "left", "right", "two" };
        String action = args[1];
        sup = false;
        for (int i = 0; i < allmeth.length; i++) {
            if (action.equals(allmeth[i])) {
                sup = true;
            }
        }
        if (!sup) {
            System.out.println(usage);
            return;
        }

        String filename = args[2];

        int threads = 0;
        if (kind.startsWith("par")) {
            if (args.length < 4) {
                System.out.println(usage);
                return;
            }
            String tup = args[3];
            String t = tup;
            try {
                threads = Integer.parseInt(t);
            } catch (NumberFormatException e) {
                e.printStackTrace();
                System.out.println(usage);
                return;
            }
            if (threads < 1) {
                threads = 1;
            }
        }

        Reader problem = null;
        try {
            problem = new InputStreamReader(new FileInputStream(filename),Charset.forName("UTF8"));
            problem = new BufferedReader(problem);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            System.out.println(usage);
            return;
        }

        RingFactoryTokenizer rftok = new RingFactoryTokenizer(problem);
        GenSolvablePolynomialRing spfac = null;
        try {
            spfac = rftok.nextSolvablePolynomialRing();
            rftok = null;
        } catch (IOException e) {
            e.printStackTrace();
            return;
        }
        Reader polyreader = new CatReader(new StringReader("("),problem); // ( has gone
        GenPolynomialTokenizer tok = new GenPolynomialTokenizer(spfac,polyreader);
        PolynomialList S = null;
        try {
            S = new PolynomialList(spfac,tok.nextSolvablePolynomialList());
        } catch (IOException e) {
            e.printStackTrace();
            return;
        }
        System.out.println("S =\n" + S);

        if (kind.startsWith("seq")) {
            runSequential(S, action, pairseq);
        }

        if (kind.startsWith("par")) {
            runParallel(S, threads, action, pairseq);
        }
    }


    /**
     * run Sequential.
     * @param S polynomial list.
     * @param action what to to.
     */
    @SuppressWarnings("unchecked")
    static void runSequential(PolynomialList S, String action, boolean pairseq) {
        List<GenSolvablePolynomial> L = S.list;
        List<GenSolvablePolynomial> G = null;
        long t;
        SolvableReduction sred = new SolvableReductionSeq();
        SolvableGroebnerBase sbb = null;
        if (pairseq) {
            //sbb = new SolvableGroebnerBaseSeqPairSeq();
            System.out
                    .println("SolvableGroebnerBaseSeqPairSeq not implemented using SolvableGroebnerBaseSeq");
            sbb = new SolvableGroebnerBaseSeq();
        } else {
            sbb = new SolvableGroebnerBaseSeq();
        }
        t = System.currentTimeMillis();
        System.out.println("\nSolvable GB [" + action + "] sequential ...");
        if (action.equals("irr")) {
            G = sred.leftIrreducibleSet(L);
        }
        if (action.equals("left")) {
            G = sbb.leftGB(L);
        }
        if (action.equals("right")) {
            G = sbb.rightGB(L);
        }
        if (action.equals("two")) {
            G = sbb.twosidedGB(L);
        }
        if (G == null) {
            System.out.println("unknown action = " + action + "\n");
            return;
        }
        S = new PolynomialList(S.ring, G);
        System.out.println("G =\n" + S);
        System.out.println("G.size() = " + G.size());
        t = System.currentTimeMillis() - t;
        if (pairseq) {
            System.out.print("seq+, ");
        } else {
            System.out.print("seq, ");
        }
        System.out.println("time = " + t + " milliseconds");
        System.out.println("");
    }


    /**
     * run Parallel.
     * @param S polynomial list.
     * @param action what to to.
     */
    @SuppressWarnings("unchecked")
    static void runParallel(PolynomialList S, int threads, String action, boolean pairseq) {
        List<GenSolvablePolynomial> L = S.list;
        List<GenSolvablePolynomial> G = null;
        long t;
        SolvableReduction sred = new SolvableReductionPar();
        SolvableGroebnerBaseParallel sbb = null;
        SolvableGroebnerBaseSeqPairParallel sbbs = null;
        if (pairseq) {
            sbbs = new SolvableGroebnerBaseSeqPairParallel(threads);
        } else {
            sbb = new SolvableGroebnerBaseParallel(threads);
        }

        t = System.currentTimeMillis();
        System.out.println("\nSolvable GB [" + action + "] parallel " + threads + " threads ...");
        if (action.equals("irr")) {
            G = sred.leftIrreducibleSet(L);
        }
        if (action.equals("left")) {
            if (pairseq) {
                G = sbbs.leftGB(L);
            } else {
                G = sbb.leftGB(L);
            }
        }
        if (action.equals("right")) {
            if (pairseq) {
                G = sbbs.rightGB(L);
            } else {
                G = sbb.rightGB(L);
            }
        }
        if (action.equals("two")) {
            if (pairseq) {
                G = sbbs.twosidedGB(L);
            } else {
                G = sbb.twosidedGB(L);
            }
        }
        if (G == null) {
            System.out.println("unknown action = " + action + "\n");
            return;
        }
        if (G.size() > 0) {
            S = new PolynomialList(G.get(0).ring, G);
        } else {
            S = new PolynomialList(S.ring, G);
        }
        System.out.println("G =\n" + S);
        System.out.println("G.size() = " + G.size());
        t = System.currentTimeMillis() - t;
        if (pairseq) {
            System.out.print("p+ ");
        } else {
            System.out.print("p ");
        }
        System.out.println("= " + threads + ", time = " + t + " milliseconds");
        System.out.println("");
        if (pairseq) {
            sbbs.terminate();
        } else {
            sbb.terminate();
        }
    }

}
